Thermal protection for shielded ignition systems



y 1941. M. F. PETERS I THERMAL PROTECTION FOR SHIELDED IGNITION SYSTEMS Original Filed Dec. 7, 1934 .1 III Illillllll I!!! hullliilll. Iiiilllllfllldlll UFNE tion cable.

. it on wire -iiange OI thatextendsradially Patented May 13, 1941.

THERMAL PROTECTION FOB SHIELDED IGNITION SYSTEMS Melville F. Peters, Beitsviile, m.

Original application December I, 1934, Serial No.

Divided and this application October 12, 1939, Serial No. 299,124

(Granted under the act of March 3, 1883, as amended April 30, 1928; B70 0. G. 757) 4Claims.

This invention relates to means for detachably connecting two electrically conducting members, and more particularlyto means for connecting a radio shielded ignition cable to a spark plug.

The principal object of my present invention is to provide connecting means of the kind specified, that are eflicient both electrically and mechanically, and are readily connectible and disconnectible.

In the drawing: v Fig. 1 is .a longitudinal axial section of one embodiment of my present invention; and

vl lg. 2 is a fragmentary sectional view showing a modified form of Fig. 1.

This application is a division of my copending application, Serial No. 756,431, filed December '7,

1934, now Patent No. 2,186,638, dated Jan. 9,

spark plug connected end of the harness to form a conductive path between the center electrode of the spark plug and the conductor in the igni- Heretofore some difliculty has been experiwhich the shielding harness 96 is clamped by a union 91, a body 98 of asbestos, relatively soft rubber or the like, disposed in a thin metal retainer 99 being so positioned that when connection- 91 is tightened down the rubber will be squeezed tightly around the cable 90 and against the adjacent end of sleeve 94 to form a tight seal and to form an electrically conducting connection, through retainer 99, between members at and 96. The flange 85 may becaught with the fingers or a screw driver to pull sleeve 94 outwardly when it is desired to disconnect the cable from the terminal 93. The sleeve 04 may be slit at its inner end or it may be inwardly bevelled or otherwise shaped to increase its effectiveness for the purpose stated. In Fig. 2 the enced' in securing an efiicient electrical connection between the spark plug and the cable where springs are used as the yielding conductive element. To eliminate this trouble, I have devised a new means of making such connection. In Fig. l is shown a hollow member If of metal that is a poor thermal conductor having in it the heat and electrical insulation 01 with the wire I of low heat conductivity embedded therein. there being a recess 8. formed in the insulating material 11 to receive the cable ll. Fixed to the wire II in cable 9. are a plurality of curved fingers II that are adapted to be spread apart when pushed against the bulbous terminal to slip around and engage said To prevent casual separation of the lingers I! from terminal ".fsieeve It is slidably. positioned on the cable ll and after the fin ers are is pushed down .to terminal. At the outer.

clamp the fingers against the end of sleeve 04 is a outwardly over theendoi'insulatinsmateriaillandagainst engaged with the germina this sleeve fingers 92 are shown provided with outwar ly turned portions 92' at their free ends. These outwardly turned portions contact the walls of recess 89 and so center the fingers 81 in proper position to engage the terminal 93.

The'invention herein set forth may be made orused by or for the Government of the United States without payment of any royalties thereon or therefor.

I claim:

1. In combination, a hollow member of electrically conducting material having low thermal conductivity, insulating material therein, there being a recess in said insulating material at one end, an electrical conductor of low thermal conductivity passing through said insulating material having a bulbous terminal in said recess adjacent the bottom thereof, an insulated cable with an end insertable in said recess, electrically conducting elements movable toward and away from each other connected to the wire in said cable at the said end thereof, said elements being normally separated sufilciently to permit of their being pushed over said terminal, a sleeve disposed around the said end of the cable slidable to lock said elements firmly upon said terminal, electrical shielding on said cable, and means to connect said shielding to said hollow member.

and simultaneously lock said sleeve against movement away from said terminal.

2. In combination, a hollow member of electrically conducting material having low thermal conductivity, insulating material therein, there beingarecessinsaidinsulatingmaterial atone end, an electrical conductor or low thermal conductivity passing through said insulating materialhavingabulbousterminalinsaidrecess adjacent the bottom thereof, an insulated cable with an end insertable in saidreoess, electrically conducting elements movable toward and away from each other connected to the wire in said cable at the said end thereof, said elements being normally separated sufliciently to permit of their being pushed over said terminal and each having an outwardly turned toe at its free end to position such free end in said recess, a sleeve disposed around the said end of the cable slidable to lock said elements firmly upon said terminal, electrical shielding on said cable, and means to connect said shielding to said hollow member and simultaneously lock said sleeve against movement away from said terminal.

3. In combination, an element having a recess therein, an electrical conductor within said element having a bulbous terminal in said recess adJacent the bottom thereof, a member including an electrically conducting portion insertable into said recess, electrically conducting fingers secured to said portion to be movable toward and away from each other and to be pushed over said terminal, means on said member movable into said recess to lock said fingers against withdrawal from said terminal, and means to force said movable means into and to secure said means in the locking position and positively to terminal, each said finger having a laterally turned portion to contact the wall of said recess and thereby position said fingers to engage said terminal, means on said member movable into said recess to lock said fingers against withdrawal from said terminal, and means to force said movable member into and to secure said means in the locking position and simultaneously positively fasten said member and said element toget MELVILLE F. PETERS. 

